Food-grade carbon dioxide high-efficiency purifying system and process thereof

Abstract

The invention relates to the field of food-grade carbon dioxide purification, and discloses a food-grade carbon dioxide high-efficiency purifying system and a process thereof. The system comprises inturn a compression power unit, a hydrolysis desulfurization unit, a fine desulfurization unit and a purification unit, and the compression power unit comprises a compressor for pressurization, the hydrolysis desulfurization unit comprises in turn a desulfurization heater and a hydrolysis desulfurization tower; the fine desulfurization unit comprises in turn a desulfurization water cooler and a fine desulfurization tower; the fine desulfurization tower is provided with, from bottom to top, a H2S desulfurization layer which is filled with a ZnO desulfurizer and a COS catalytic oxidation layer which is filled with iron filings, an ozone supply pipe is connected between the H2S desulfurization layer and the COS catalytic oxidation layer; and the purification unit includes in turn a dehumidifier, a precooler, a condenser and a purification tower. According to the system and the process, the working temperature of the hydrolysis desulfurization tower is regulated down, and the flow rate in the hydrolysis desulfurization tower is regulated up, and residual COS and H2S are oxidized for removal, therefore the quality of a finished product carbon dioxide is improved, the desulfurization efficiency is high, the cost is economical, and the effect is remarkable.

Description

technical field [0001] The invention relates to the field of food-grade carbon dioxide purification, in particular to a food-grade carbon dioxide high-efficiency purification system and a process thereof. Background technique [0002] Carbon dioxide is a colorless, odorless, non-flammable gas that can be compressed to high pressure. Currently, it is used according to the content and purity of carbon dioxide. The current application direction includes the use of high-purity carbon dioxide in the beverage and beer industry, and high-purity carbon dioxide in the tobacco industry. Used as tobacco expansion agent, food preservation, industrial raw materials, medical and health respiratory stimulants, etc. In recent years, my country has intensified its efforts to promote sustainable development, and the country's carbon emission policy has become increasingly tight. All provinces have corresponding carbon emission quotas, and enterprises are under great pressure to reduce emissio...

AI Technical Summary

Problems solved by technology

[0005] But there is still H in the existing hydrolysis tower 2 S reacts with oxygen to form a side reaction of S. The formation of S will aggravate the sulfation of the organosulfur hydrolysis catalyst, leading to the failure of the active center of the organosulfur hydrolysis catalyst, and the COS hydrolysis conversion efficiency of the organosulfur hydrolysis catalyst decreases and the service life is reduced. This is to prolong the service life of the catalyst. At present, the temperature in the hydrolysis tower is lowered, and the residence time of the raw material gas in the hydrolysis tower is reduced.

However, after corresponding adjustments are made, COS residues exist in the feed gas from the hydrolysis tower to the next process in the actual production process. The COS residues fluctuate greatly, and the upper limit of the fluctuation value increases with the prolongation of the production cycle, which affects the product carbon dioxide content index. Difficulty in control, when product inspection, some food-grade indicators are not up to standard or even industrial-grade indicators are not up to standard

In addition, in the production process, it is also attempted to connect a small hydrolysis tower to the existing hydrolysis tower for further hydrolysis, but the effect is not satisfactory, and the operating costs such as equipment products and catalyst loss during operation are relatively high

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